Cooling system Nightmare

[Triumph fan]

Posted in the tech section aswell as i need help desperately.

2003 Cooper,weeping bottom rad hose about six months ago,repaired and all was well.recently the clutch went and we had a new one put in at our local garage,clutch is good now but,when it came back it overheated and the water had all gone,bottom fitting leaking again.Heater is stone cold and the gauge shoots to the red zone when running.

I have fitted a new rad and new thermostat housing and stat,bled it god knows how many times,also had the heater rad out yesterday,it had old brown water in it so i have cleaned it and blown through the pipes.

Still the same with the system pressurizing and the fan running but heater pipes stone cold and gauge on max.

Help appreciated.
Steve

[mab01uk]

Is the rad fan working on both speeds.....(I assume you have air con which has the 2-speed fan), 2nd speed is very loud but if lower speed fan resistor has failed engine will tend to overheat before the high speed fan kicks in.

Have you checked the sealing of the engine pressure cap (not expansion tank cap)?

The dash temp gauge is not accurate but their is a way to get the speedo display computer to show actual water temp on the digital display:
This is great for fault diagnosis. You will be able to see the thermostat controlling the temp as you drive and when stationary you can check the fan comes on at low speed at around 106C.
http://www.mini2.com/forum/first-gen...ml#post3828926

Lots of helpful links and cooling system info here:
Solving MINI Cooling Problems.......... - Forums

Other Mini forums to try for help/advice/search:
http://www.totalmini.com/forum/

USA:
http://www.northamericanmotoring.com...lems-issues-9/

[Triumph fan]

System pressure cap seems ok,i have tried the original and the new one that came with the thermostat housing.Two speed fan is working as far as i can tell,the coolant gets hot fairly quickly around the right side of the engine around the thermo housing and pipes but the heater pipes remain cold and hot water doesn`t seem to circulate.

I am going to remove the jiggle pin from the new thermostat and investigate the pump,some of the other posts point towards head gasket failure
Steve

[mab01uk]

Head gasket failure due to severe overheating earlier can be detected with a kit which detects the presence of HC exhaust gases leaking into the coolant, while any oil in the coolant should be more obvious.

Are you sure coolant can circulate through that matrix in and out and is not blocked, does not make sense it is remaining cold unless water pump has failed and is not pumping?

[Triumph fan]

Sorted at last!

I had an aftermarket thermostat which i tested in some boiling water,nothing-so i bought a genuine one,same problem with cold heater and gauge to the max.

Took the pump off and it seemed very loose,as if the impeller wasn`t turning with the shaft,fitted a new pump and all was well with the system and the heater.

The gauge never moves from normal and the heater is roasting,the fan hasn`t kicked in once as it runs a lot cooler with a new rad and thermostat.
Steve

[mab01uk]

Thanks for reporting back on the water pump as it helps others in the future.......glad you have fixed it.